Project (Impacts of Computer-mediated Caregiver Support Groups) evaluates the effectiveness of two types of computer-mediated support groups (CMSGs) for family caregivers of persons with dementia. The study addresses four key questions: 1) To what extent are theoretically- derived goals of CMSGs achieved in practice? 2) Which caregivers are most likely to use CMSGs? 3) Does CMSG participation ameliorate the negative outcomes of caregiving? And 4) Does the impact of CMSGs vary by type of leadership (professional versus lay)? The project consists of three complementary studies (A-C) using a sample drawn over a two- year period from caregivers enrolled in the ADRC Caregiving Core registry. Both clinical and Caregiving Core data are used. The analysis plan draws on the technical expertise and resources of the Data Management and Analysis Core. Study A is a normative evaluation of the intended intervention to determine the extent to which CMSGs actually accomplish the purposes and impart the benefits of dementia caregiver support groups envisioned by program planners. A content analyses of the peer-to-peer communications of CMSG members will be conducted, group participation patterns will be coded, and group users will be asked to report perceptions of benefits and drawbacks of participation. Study B involves both normative and causative components. The normative component addresses intervention targeting by modeling the relationship between caregiver demographic, personal, and situational characteristics and use of a CMSG. The causative component assesses the impact of CMSG participation on caregiver psychosocial resources and the stresses and outcomes associated with caregiving. The study builds on the Stress Process model and uses multi-level longitudinal analyses to test hypotheses. The study builds on the Stress Process model and uses multi- level longitudinal analyses to test hypotheses. Study C is an exploratory causative analyses of possible unintended impacts of MSG use and of ways in which CMSGs might be made more compatible with the needs of intended users. Study C is a thematic analyses of results of semi- structured interviews with a purposive sample of participants in Studies A and B. Results of Project 3 will provide new information on the capacity of computer-mediated communication to provide support services to family caregivers and the relative contributions of professional and peer leadership to achieving positive support group impacts.